This invention relates to an infusion unit for use in medical services and, in particular, to a kit capable of dissolving a powder medicine into a solvent liquid or a diluent liquid immediately before use, with a very simple operation.
In medical institutions, various medical kits combining medicines and medical instruments are widely used in order to reduce work load in preparation of doses and to prevent bacterial contamination and entry of foreign matter.
Generally, an infusion fluid for drip injection is prepared before every use by removing powdery medicine from a vial and dissolving it into a diluent liquid such as a sugar solution or a saline solution. Because of frequent use of such infusion solution, there has been a longstanding demand to simplify preparation.
A conventional infusion unit or kit generally comprises a holder for holding a medicine bottle or vial with a mouth at one end thereof sealed by a pierceable mouth-plug, a flexible liquid container and communicating means for communication between the medicine bottle and the flexible liquid container. The communicating means comprises a piercing needle provided on the vial and a tear member provided on the flexible liquid container. After the mouth-plug which is typically made of rubber, has been pierced with the piercing needle, the tear member is manually torn off so that the medicine bottle and the flexible liquid container communicate with each other (Japanese National Laid-Open Publication No. Sho 61-501129). The communicating means may also comprise a double-pointed needle, so that both the medicine bottle and the liquid container are pierced with the doublepointed needle for communication therebetween to allow the contents to mix (Japanese Patent Laid-Open Publication No. Hei 2-1277).
However, the above-mentioned first conventional infusion unit with the tear member requires a troublesome tearing operation. If the tearing operation provides an insufficient opening, dissolution takes a long time because only a small quantity of medicine is able to flow through the opening. In addition, scraps of the tear member may be dropped into the infusion solution. The above-mentioned second conventional infusion unit with the double-pointed needle requires control means of a special design for controlling communication in such a manner that one end of the double-pointed needle first pierces through the mouth-plug of the medicine bottle before the other end pierces through a sealing film of the flexible liquid container. Since the operation of the control means cannot be known intuitively, an operator may get confused in case of emergency.
The present invention provides an infusion unit which is capable of assuring a tight seal of a liquid container before use and which is capable of establishing reliable communication between a medicine bottle while avoiding the problems of the prior art.